Among in-wheel motors that are disposed inside a wheel to drive the wheel, some of them employ techniques of offsetting a motor from the rotation axis of a wheel hub, and are conventionally known in disclosures such as, for example, Japanese Patent No. 5766797 (PTL 1). The in-wheel motor (motorized hub) disclosed in PTL 1 includes a hub coupled to a wheel of a wheel assembly, a brake shaft extending along an axle and coupled to the hub at one end, and a disc-shaped brake rotor coupled to the other end of the brake shaft. The brake rotor has an outer diameter about a half of the inner diameter of the wheel. The hub is disposed inside the wheel. An electric traction unit (motor), which drives the hub, is disposed away from any of the hub, brake shaft, and brake rotor.